The United States implemented a key element of its strategic shift toward Asia Thursday with the arrival in Japan of the Navy's nuclear-powered aircraft carrier the USS Ronald Reagan.

In addition to projecting American power in Asia, the U.S. warship’s forward deployment is a show of support for Prime Minister Shinzo Abe’s controversial efforts to expand the Japanese military's role in the region.

The USS Ronald Reagan, which carries 5,000 people and more than 60 aircraft, is at the center of the United States' Asia "pivot," focusing military and diplomatic assets on a region of increasing strategic importance.

Growing regional threats

China’s claims to islands in disputed waters and its recent land reclamation work in the South China Sea has drawn protests from the Philippines and Vietnam, which also claim rights in the region.

And its claims to international waters, where more than half of the world’s maritime trade passes through, could threaten the freedom of navigation.

North Korea’s growing nuclear program and long-range missile development is also a concern to U.S. national security.

The aircraft carrier serves as a rapid response force to any provocation that might develop in the region. It also coordinates a striker force that includes an increasing number of military assets.

“We have ships that are extremely capable [of] ballistic missile defense, especially in this region of the world right across the ocean from North Korea,” said Vice Admiral Joseph Aucoin, commander of the U.S. Seventh Fleet.

Aucoin also confirmed reports that the Navy’s Third Fleet headquarters in San Diego will expand its engagement in the Western Pacific region to coordinate, when needed, with the Japan-based Seventh Fleet.

Japan’s security posture

The USS Ronald Reagan’s presence in Japan coincides with the passage of new security measures that should make it easier for the Japanese military to act in defense of its interests and its allies.

While Prime Minister Shinzo Abe and his conservative coalition were able to get the measures passed, they encountered strong pacifist opposition at home and regional concerns that Japan was returning to its militaristic past.

U.S. Navy Secretary Ray Mabus was at the USS Ronald Reagan arrival ceremony Thursday and voiced U.S. support for a more assertive Japan to help deter common adversaries like China and North Korea.

“So we think that these new measures will deepen that, will strengthen that and will make us better together,” Mabus said.

But security analyst Grant Newsham, with the Forum for Strategic Studies in Tokyo, said for Japan to be more than a junior partner to the U.S. it must start by increasing defense spending by 10 percent for five years.

“If Japan doesn’t boost its defense spending, then there is always going to be doubt as to how serious they are,” Newsham said.

He also said Japanese Defense forces must commit to more intense and integrated training with the U.S.

“The traditional approach has been for both sides to train in parallel and then at the end have a barbeque party in which they claim they are the best of friends,” Newsham said.

Operational lead

Japanese forces, he said, must also take the lead on potentially dangerous missions instead of just offering logistical support.

The aircraft carrier’s multiyear deployment in Asia is not in itself an increase of U.S. military assets in the region. The United States has maintained one of its 10 aircraft carriers in Asia for decades.

The USS Ronald Reagan also provided humanitarian assistance and relief to area in Japan affected by the 2011 Sendai earthquake and tsunami.